Hydraulic governing mechanism



July 15, 1941. D. F. WARNER HYDRAULIC GOVERNING MECHANISM Filed April26, 1939 Inventor: Donald F War-her,

His Attornes.

UNiTED I STATES PATENT OFFICE.

HYDRAULIC GOVERNING MECHANISM Donald F. Warner, Swampscott, Masa,assignor to General Electric Company, a corporation of New York 1Application April 26, 1939, Serial No. 210,165 5 Claims. (c1. 12146.5)

The present invention relates to hydraulic charged therefrom through aconduit l3 which is governing mechanisms comprising a servo-motorconnected to a fluid pressure supply conduit 20 and a control or pilotvalve for controlling the through the intermediary of a control or pilotflow of fluid under pressure to the servo-motor valve 2|. Positioning ofthe pilot valve 2| is such as are used, for example, in connection withefiected in response to changes of pressure in elastic fluid turbines toposition the inlet valve the aforementioned conduit l3. To this end tthereof in response to changes of a fluid conconduit I3 is connected bya pipe 22 to the fixed dition. More specifically, the invention relatesend of a Bourdon tube 23 which has a free end to governing mechanisms asmay be used for 23 connected by a link 25 to the left-hand end of ontoll n flu d p ss r f s d a e a nia floating lever 26. The latter has anintermeditud he Pressure-responsive device forming ate point connectedby a link 21 to the pilot P Of e mechanism in these cases 115119413 isvalve and a right-hand end pivot-ally connected in the form of a Bou dotu e WOrk to a lever 28 engaging a fulcrum 23 and having a P ity of aBourdon tube is small because such left-hand end connected by a link 33to the lefttubes possess small stroke and little directive hand end ofmm; 1 3| Th ht-hand force. The pilot valve then which is controlled endof t lever 31 s fastened t shaft 32, y t Bollrdon tube must bePractically 69 of which latter has a portion secured to the leftstaticand viscous friction. It also should cause h d d of th follow-up l verla, The haftdz small reaction to the flow of oil therethrough. isupported on a fulcrum 33 which may be The general Obj t of my inventionis to p 510 formed by the side walls of a casing 34 for the Vide an p dConstruction and a a g mechanism; The short lever 3| is located insideof hydraulic governing mechanisms Of the type the casing 38 whereas thelong lever i3 is 10- Patented July 15,1941 2,249,508

a ove sp ifi d which des a special pilot cated outside the casing 34 andhas its leftvalve that may be readily controlled by the small hand endsecured to a portion of the shaft 32 directive force of apressure-responsive device projecting through the casing side wall. Asfar such as a Bourdon tube. as the operation of the mechanism isconcerned.

For a consideration of what I eli e to b we may consider the two levers3!, It as a single 1 I novel and my invention, attention is directed tolever held on a fulcrum 33. The lower end of the fbll i description t eClaims appended the aforementioned link is guided in a bearing theretoin connection with the a c mp y 30 35. The fulcrum 29 for the lever 28maybe addrawing. justable to vary the operation of the mechanism. n t ed aw g. 1 illustrates a hydraulic The operation of the mechanism is asfollows, overning me anism e dy y n n assuming for the present thatupward movement Fig. 2 is a Sectional View t u t e pilot W of the link21 causes the pilot valve to increase f 3 is a t p v w part y in sectionthe restriction of the flow of fluid from the conf and vFig- 4 is n eploded perspecduit 20 to the conduit l9 or disconnect the contive viewof certain parts of Fig. 2. duit; and vice versa, that downward movementThe mechanism i F 1 s been Shown -P- of the link 21 decreases therestriction of the plied to an elastic fluid turbine id with an inletflow of fluid from the conduit 23 to the conduit valve H and arran ed todrive a c ntrifu al time I9. Increase in pressure in the pipe 22 which Dp 0 o pre or 52 with discharge conduit may be due to a decrease indemand for fluid 13. In sucharrangement it is often required to underpressure from the compressor forces the maintain the high dischargepressure in the disfree end 26 of the Bourdon tube 23 upward chargeconduit l3 substantially constant durwhereby the left-hand end of thefloating lever ing variations in load. This is accomplished in 26 ismoved iup and causes upward movement accordance with my invention bymeans of a of the link Zi, resulting in increased restriction hydraulicgoverning mechanism which comprises to flow of fluid from the conduit 20to the cona hydraulic motor l t with a piston i5 biased duit l9 andconsequently decreasing fluid presdownward by a compression spring itand se- 5 sure in the hydraulic motor I4 whereby the piscured to a stemll. The stem W has a lowerton is moved downward by the action of theextension connected to the turbine inlet valve spring l6 and causesclosing movement of the II and an upper end pivotally secured to aconturbine inlet valve II. This reduces the flow of trol or follow-uplever l8. Fluid under pressure operating fluid to the turbine 13 so thatthe is supplied to the hydraulic motor H and dis- 55 speedof the latterdecreases, resulting in a dethe fulcrum 29.

crease in pressure in the compressor discharge conduit I3. During upwardmovement of the left-hand end of the lever 26 by action of the Bourdontube the right-hand end of the lever 26 remains stationary, acting as afulcrum. Down- Ward movement of the piston I5 of the hydraulic motorcauses downward movement of the follow-up .lever I8 whereby theleft-hand end of the short lever 3| is moved upward, causing clockwiseturning movement oi the lever 28 about The right-hand end of the lever28 then is moved downward, causing downward movement of the link 21 andrestoring of the pilot valve to its original position.

The pilot valve which forms an essential part of my invention is shownin detail in Figs. 2 to 4 and comprises a block 40 forming an inletchannel 4| and an outlet channel 42, the channel 4| being connected tothe supply conduit 29 to receive fluid under pressure therefrom and thechannel 42 being connected to theconduit I9. The function of the pilotvalve, as described above, is to control the restriction to flow offluidunder pressure between the channels M and 42.

The arrangement, as best shown in Figs. 2

and 4, comprises a plurality of plates 43, 44, 45,

46 and 41. The plate 43 forms an inlet or feed port 48. The plate 45forms a supply and discharge port 49, more specifically a port ofcontrolled pressure which communicates with the channel 42 in the blockthrough bores 59 and 5| in the plates 43 and 44 respectively. The upperplate has a cut-oil or recess 52 through which operating fluid may. bedrained, as will be de- In the position shown in Fig. 2 the pocket 45registers with the lower edge of the plate 44 and the upper edge of theplate 48. In this position the pocket 54 communicates with the port 49but does not communicate with the port 48 or the draining recess 52 sothat no flow of operating fluid takes place, except for leakage throughthe clearance between the member 53 and the valve assembly, meaning thatthe apparatus is in equilibrium. If the member 53 is moved downward itestablishes connection between the ports 48 and 49, thus permitting theflow of fluid from the port 48 through the port 49 to the hydraulicmotor. The restriction to the flow between the ports decreases as thevalve member 53 is moved further down and minimum restriction to flowand accordingly maximum pressure in the hydraulic motor is attained whenthe lower edge of the pocket 54 registers with the upper edge of theblock 42, contacting the lower edge of the feed port 48. All of theaforementioned plates 43 to 41 inclusive are securely fastened to thevalve block 40 by means of screws 51. The movable valve member 53 formsan arm or lever which is hinged at its right-hand end by means includinga pin 58 rotatable in an eccentrically bored sleeve 59 held in a bore 88of the block 40. The sleeve 59 normally is held in position by a setscrew 8|. An extension of the sleeve outside the bearing 80 has cut-01fportions 62 whereby the sleeve may be adjusted upon loosening of the setscrew 6|.

Positioning of the sleeve permits adjustment of the clearance betweentheadjacent faces of the pocket forming valve member 53 and the plates 43to 41. The left-hand end of the movable valve member forms an opening 83for pivotal connection with the link 21. The movable parts of themechanism in particular the element 53 is biased by means of a spring 64having an end portion positioned in a recess 65 of the block 49 andanother end portion positioned in a recess 88 of the movable valvemember. The spring eliminates error in position due to manufacture orsubsequent wear of parts. The aforementioned casing 34 for enclosing themechanism has a bottom 61 with a drain port 88. The pilot valve block 40is secured to the bottom 81 by means of bolts 69.

During operation, increase in pressure in the conduit I3 causes, asdescribed above, upward movement of the link 21 whereby the movablevalve member 53 is moved upwardv and permits draining of fluid from thehydraulic motor through the conduit I9, the discharge port 49 and thedrain port or recess 52. This fluid is discharged through the drainconduit 88 of the casing. Similarly adrop in pressure in the conduit I3causes downward movement of the link 21, thus establishing connection.between the ports 48 and 49 and supply of fluid under pressure from theinlet conduit 20 through the pilot valve and the conduit I9 to thehydraulic motor l4, resulting in opening of the turbine valve II.

With this arrangement the slightest movement of the valve member 53establishes a change of fluid pressure in the hydraulic motor. Thehydraulic characteristics of this pilot valve are similar to that ofordinarypilot valves with round valve heads. The static and viscousfriction of this pilot valve, however, are relatively very small ascompared with those of cylindrical type valves. The only bearingfriction is between the eccentric sleeve 59 and the pin 58. At thispoint the angular movement is slow and the to a Bourdon tube and anotherpoint connected to a follow-up device. All these elements are enclosedwithin a casing which at the same time forms a drain channel forreceiving operating fluid discharged from a pilot valve drain port.

The pilot or control valve itself broadly comprises a block which formsinlet and outlet channels and a laminated structure in the form ofseveral plane-plates fastened to the block and forming .a feed portcommunicating with the inlet channel, a port of controlled pressurecommunicating with the outlet channel and a drain port for receivingoperating fluid which under certain conditions is discharged from theoutlet channel. The restriction to flow of fluid between the severalports is controlled by a movable valve member which forms a pocket incooperative relation with the ports and is held on the block by means ofan eccentric sleeve and biased by means of a spring.

Having described the method of operation of my invention. together withthe apparatus which I now consider to represent the best embodimentthereof, I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means. I

the inlet and the outlet channel respectively, a

I movable valve membertc establish connection What I claim as new anddesire to secure by LettersHPatent oi the United States is:

1. A control valve comprising a block formin inlet and outlet channels,a laminated structure having a plurality of plates secured to the blockand including a flrst plate forming a flrst port in communication withthe inlet channel, a

second plate forming a second port in communication with the outletchannel and a third plate forming a drain port, and a movable valvemember in cooperative relation with the ports to control the restrictionto flow of fluid between them.

between the ports and to control the restriction to flow oi fluidbetween them, and means adiustably pivoting the movable valve member onthe block. Y

4. A control valve comprising a block forming inlet and outlet channels,a laminated structure including a plurality of plates se'cured totheblock, one of said plates forming a feed port communicating with theinlet channel, a second plate forming a. port oi! controlpressure-communicating with the outlet channel through a bore in thefirst plate, a third plate forming a drain port, a movable valve memberin cooper'ative relation with the-ports for controllin'g the restrictionto flow oi fluid from the feed port to. the port of control pressure andfrom. the

latter to the drain port.

5. A control'valve comprising a block forming two channels, a. pluralityof plates secured to the block and including a first. plate forming aflrst port, a second plate forming a second port,

the port in the flrst plate communicating di- 1 rectly with one of thechannels, means including an opening in the first plate and anintermediate plate with an opening located between the flrst and thesecond plate to connect the second port with the other channel, and amember pivotally held on the block for controlling the communicationbetween the flrst and the secondport. DONALD F. WARNER.

